Get all rows with specific time difference

Question

Hello i have a table like this:

|user_name|pw|register_date|last_time_entered

I want to get all the rows where last_seen_date - register_date < 7

I dont know how to write this query i thought about something like this

SELECT * FROM workoutlog_1.personal 
WHERE DATEDIFF(day, workoutlog_1.personal.register_date, workoutlog_1.personal.last_time_entered) < 7;

But i get this error:

Error Code: 1582. Incorrect parameter count in the call to native function 'DATEDIFF'

Thanks for helping.

Answer 1

Your error code seems to come from mysql.

With mysql, datediff takes only 2 parameters ( day is not needed)

I think that in (really) old versions, it took 3 parameters, now it works only with 2, and it will return days.

If you had to work with another unit (hour for example), you could use TIMESTAMPDIFF

Answer 2

MySql's DATEDIFF differs from SqlServers DATEDIFF in that it takes only 2 date parameters, and returns the difference in days. Since you want days anyway, just remove the day parameter, ie

SELECT * FROM workoutlog_1.personal 
WHERE DATEDIFF(workoutlog_1.personal.register_date, 
               workoutlog_1.personal.last_time_entered) < 7;